Sure, go wild. You can't really hurt anything as long as you know a somewhat sane setting to go back to. Or just delete it to go back to stock.
Code:
$ settings get secure sysui_nav_bar
space[0.25WC],back;home;recent,space[0.25WC]
$ settings delete secure sysui_nav_bar
Deleted 1 rows
$ settings get secure sysui_nav_bar
null
The most recent Android has more options. Even if you don't code, you can see the options in this file and try them out.
https://android.googlesource.com/pla...laterView.java
I have no idea what I'm doing!